With a rapid growth of the amount of mobile users and a great increase of high-rise buildings, traffic density and coverage requirements are constantly rising. Most of existing buildings with large scale and good quality have a strong shielding effect upon mobile communication signal. In lower floors of large-scale buildings, underground shopping malls, underground parking lots and other environments, there are blind spots and shadow areas of mobile communication, where mobile communication signal is so weak that mobile phones can not work properly. Further, in middle floors, since signals from different base stations overlap, resulting in ping-pong effect, the mobile phones are switched frequently and even get calls dropped, which seriously affects the normal use of mobile phones. High floors of buildings, due to restrictions by the height of the base station antenna, can not be properly covered, where the blind spots of mobile communication are also formed. These have caused that the mobile users are not able to normally use their mobile terminals.
To this end, indoor network coverage test technologies have been applied in construction of mobile communication network. During the indoor network coverage test, an indoor drive test terminal can realize a collection operation of wireless interface data in relation to multiple modes in accordance with a predefined testing scheme or real-time instructions of a drive test platform; a hand-held terminal (such as, tablet PC, mobile phone and notebook) cooperatively used with the indoor drive test terminal may display indoor advancing track. In combination of the data collected by the indoor drive test terminal and the advancing track of the hand-held terminal, the network coverage condition of various indoor positions can be tested.
However, during the testing of the indoor drive test terminal, there is no GPS (Global Positioning System) signals under most environments, so a gyroscope is usually used to realize indoor location. The gyroscope generally includes a tri-axial angular velocity meter, a tri-axial accelerometer and a tri-axial magnetometer. When the gyroscope is used to realize the indoor location, adaptive Kalman data fusion algorithm is generally adopted. The algorithm necessarily performs indoor location in accordance with a directional angle of the indoor drive test terminal. Usually, when setting the directional angle, the indoor drive test terminal may set by adopting a deviation between the magnetometer angle and the due north angle in conjunction with the shape of the building, so as to determine the directional angle of the indoor location.
That is, the existing schemes for indoor location depend on the magnetometer. However, there is a great amount of electro-magnetic interference in the indoor environment, such as entrance guard system, elevator room and etc. Thus, the magnetometer may be interfered to cause the magnetometer to be unreliable and to generate a significant deviation, such that the directional angle of the indoor location could not correctly determined, and then the indoor network coverage test is inaccurate.